The human eye blinks an average of 4,200,000 times a year.
233
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
There are glasses which allow a red-green color-blind person to see colors the way everyone else does.
22
Every human spent about half an hour as a single cell.
144
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Due to the angle at which the optic nerve enters the brain, staring at a blue surface during sex greatly increases the intensity of orgasms.
252